Machine tool



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MACHINE TOOL Filed Sept. 26, 1941y 15 Sheets-Sheet 7- ATTORN l E. P.BULLARD, 3D., ET A1. 2,352,185

June 27, 1944.

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MACHINE TOOL Filed Sept. 26, 1941 15 Sheets-Sheet 13 ago A nnNFY June27, 1944.

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MACHINE TOOL Filed sept. ze, 1941 `15 sheets-sheet 15 Patented June 27,1944 MACHINE TOOL Edward P. Bullard, III, Fairfield, Le Roy E.Alvey,Bridgeport, and Frank H. Mussler, Stratford, Conn., assignors to TheBullard Company, a corporation of Connecticut' Application September 26,1941, Serial No. 412,490

46 Claims. (Cl. `2li-29) This invention relates to machine tools of thetype including a transmission for moving a member along one or morepaths at a plurality of speeds, and particularly to a combined fullyautomatic and manual control for the transmission. .f

The principal object of the invention is to provide a fully automaticcontrol for the feedworks transmission of a machine tool, adapted tooperate the transmission throughout any cycle including any combinationof operations of which the machine tool is capable, and one that isadapted to permit manual control of the machine tool without affectingthe automatic setting of said control. v

Other objects include, the provisionA of a con'- trol for a machine toolincluding fluid-actuated means for rendering eiectivev the feedworkstransmission thereof that is adapted to be automatically operated inaccordance with a predetermined setting and manually operated withoutaffecting Said predetermined setting; the provision of such a control inwhich the means that is adapted manually to operate the :duid-actuatedmeans cooperates with-means common to the `automatic operating means;the provision of a control for a machine to'ol including a pattern drumandl Huid-operated mechanism for -indexling the drumvarying amounts andin opposite directions for performing different functions; the provisionYof a combined fully automatic and manual Lcontrol for the feedworkstransmission of a machine tool that can be manually set forautomatically directing the operation of the transmission to produce asequence of functions in a predetermined order, to eiect stopping of f35the transmission upon completion of the function being performed at anytime, to eect a repetition of the function being` performed or justcompleted, and to eect instant stopping of theV transmission at anytime; the provision of Va transmission control for a machine tool, the

operation of which is initiated by a force separate from that developedby the movement of :the member driven by the feedworks and whichoperation is effective instantly upon said member arriving atpredetermined points along its paths of travel; the provision of amachine tool in which a plurality of relative movements are adapted tobe provided between a tool support -and a work support along one or morepaths, and Aa fully automatic control therefor, the activity `of whichis initiated by avsource of power sep- "arate from `that incident to,but which source `is rendered effective by the relative vmotion beitween thework andtool supports; and-the provision of .a machine toolcomprising a tool and work support between which relative motion isadapted to be applied including a plurality of slow feeding speeds andafast traverse speed, and an automatic control for saidmachine tool thatis capable of selecting the path, speed and direction of said Irelativemovement between said supports for producing a plurality of functions,and in which a time-delay is rendered effective each time the fasttraverse relative movement is provided between said supports.

The above, other objects and novel `featuresl of the invention'willbecome apparent from the followingspecication and accompanying drawings,inwhich:`

, Figure 1 is a front elevational View of part of a machine-tool towhich the principles of this invention have been applied;

. Figurez is a sideelevational view, partly in section, of the machinetool shown in Figure 1; Figure 3 is a sectional plan view takensubstantially along the line 3-,3 ofV Figure.2; v

Figure 4 is a sectional stretch-out view taken substantially along .theline 4-4 of Figure 6;

Figure 5 is a perspective view of the internal .construction of thefeedworks unit;

Figure 6 is a front yelevational View of the feedworks bracket withparts removedshowing an end elevational viewv of the gearing disclosed`in Figuresll and 5;

Figure 4'7 is a sectional plan view with certain partsV being brokenaway to show others, and taken substantially along line 1-1 of Figure 6;

Figure 8 is an elevational View taken substantially along line 8 8 ofFigures 1 and 6;

Figures 9 and lllare schematic diagrams of the ,iiuid system of theapparatus;

`Figurell is a sectional plan view of the con- ,tr'ol vmechanism .withcertain parts broken -away Lto 'show others, and taken substantiallyalong line 'fit-ll of Figure 2; l

Figure12 is a sectional elevational view taken `substantially along linel2-I2 of Figure 11;A

Figure 13 is a sectional elevational view taken substantially along lineI3-I3 of Figures 11 'and 12;

falong line |5-I5 of Figures 12A and 16;

Figure'l is an elevational view, partly in section, and takensubstantially along line lS-IB of Figure :171; i

Figurel isa sectional view taken substan- 't5 tially along line I'l-llof Figure 11;'`

Figure 24 is a plan view taken substantially along line 24-24 of Figure23;

Figure 25 is a sectional elevational View taken substantially along line25--25 of Figures 11 and 13; and

Figures 26 and 27 are views 0f a detail of the invention.

Although the principles .of the invention have been shown and will bedescribed as applied to a vertical turret lathe, they may be appliedwith equal facility to any type of machine, irrespective of whether itis used to machine metal, wood, et cetera, which machine includes one ormore tool-supporting members adapted to be moved along one or morepaths.

This application contains subject matter similar to that of applicationSerial Number 345,772, led July 16, 1940, by E. P. Bullard III et al.

. Referring to the drawings and particularly to Figs. 1 and 2, theinvention is shown as applied to a vertical turret lathe including astandard S to the bottom of which isintegrally joined a base B. Awork-:supporting table W is mounted on the top of the base B and isprovided with a vertical spindle journaled in bearings Within .saidbase. A head-stock transmission I-I (Fig. 2), within standard S,receives` its power from a motor (not shown) .and .drives the rotatablework-supporting table W .at .a plurality of speeds.

A turret head T, adapted to support a plurality of tools for performingmetal-working operations, is mounted on ithe. front 4of `the standard Sfor reciprocation along intersecting paths. A feedworks F (Fig. l) ismounted on the standard S, in operative position relatively to theturret T, and is adapted to provide a power transmission for moving the`turret T along its intersecting paths at a plurality of speeds for,feeding the turret during a cutting operation,.and.at a constant,relatively rapid traverse speed for moving the turret T -into Yand outofoperating position relatively .to the work on the table W. The powerfor the feedworks F is supplied from the headstock transmission Hthrough ,suitable gearingand shafts which pass Ythrough a gear bracketG, located on the top of the standard S, thence outwardly and downwardlylinto the feedworks F.

A control unit C isV attached to the feedworks 1F `and is adapted toautomatically control ythe operation of the feedworks F for reproducingevery direction and rate, or sequence of directions and rates ofmovement of said turret head that caribe accomplished with the apparatusby an individual.

Referring to Figs. 1 and 2, the standard S .comprises a substantiallyhollow casting I having bearings II along opposite inner walls forsupporting the headstocktransmission H. The base B comprises asubstantially cylindrical hollow portion I2 cast integrally-with thelower portion of the standard S. The lwork-supporting table W comprisesa circular disc I3, provided with radially-disposed grooves I4 withinwhich chucking members are adapted to be mounted foren- .gaging the`Work.

The headstock transmission H comprises a housing I5 having bearingportions I6 that engage the supports I I within the standard S. Thetransmission I-I forms no part of the present invention. It is fullydescribed and claimed in co-pending application, Serial No. 306,122, ledNovember 25, 1939, in the name of Edward P. Bullard III et al. Thetransmission H, therefore, will be described only in so far as it isnecessary to show its relation with respect to certain features of thepresent invention. Various gear combinations within the transmission Hare adapted to be engaged by the operation of gearshifting levers I1 andI8 mounted on the forward end of a gear-shifting bracket I9. When apreselected gear combination is engaged, a combined brake and clutch 20is adapted to be shifted to disengage the brake and engage the clutch bya shift lever 2 I. The transmission H is adapted to drive a bevel gear22 at a plurality of different speeds. The gear 22 meshes with a bevelring-gear 23 xed to the lower surface of the work-supporting table W.

The tool-supporting turret T V,comprises a member 24 rotatably mountedon a pin fixed to the lower end of a turret slide 25 adapted to bereciprocated in guide bearings 26 formed in -a swivel 21. The swivel 21is mounted on a. saddle 28 having an arcuate bearing groove 29 withinwhich a connecting element of the swivel is adapted to t. Limitedoscillatable movement of the swivel 21 may be obtained by rotating aworm 30 that meshes with a rack 3 I on the saddle 28. The saddle 28 issupported o n a slide bearing 32 of a cross-rail 33. The cross-rail 33is mounted for vertical reciprocation along guide bearings 34 formed oneach side of the standard S.

The turret T is moved horizontally along the slide bearing 32 of thecross-rail 33 by a hori- ,zontally-disposed screw 35, threaded into aboss 36 on the back of the vsaddle 28. Reciprocation of the turrethead'T along bearings 26 is elected bythe rotation of a screw 31journaled in a bea'ring (Figs. 2 and 9) in the lower end of swivel 21,and threaded linto ,-an vinternally-threaded boss 39 fixed to the backof the slide 25 near the top thereof. The rotative movement of the screw31 Vbear a definite relation to the rotation of the work-supportingtable W, as well as tobe rotated at a substantially constant, relativelyrapid speed, two independent sources of power must be supplied tothefeedworks F. Accordingly, the transmission His provided witha drivinggear 46 fixed to its driving shaft at the vpower input side of thetransmission adjacent lthe combined Vclutch and brake 20. The gear=4`6,therefore, rotates at a constant speed irrespective of the speed atwhich-the ltransmissi,on H yclrives the work-supporting table W. Thedriving gear 46 meshes with a spur gear 41 fixed to one end of a shaft48. The opposite yend of shaft48 is provided with a bevel gear-49 thatmeshes with aibevel gear 50 fixed to one .end of vertically-disposedshaft 5I. A nadditional driving .gear 52 is adapted to mesh with a. gear53 fixed to the driven shaft of-'the transmission H adjacent the poweroutput side thereof. Accordingly, the driving gear 52 is adapted to berotated by the transmission H at a speed directly related to the speedat which the work-table W is driven. The driving gear 52 is xed to astub shaft 54 which supports a bevel pinion 55 at its opposite end. Thebevel pinion 55 meshes with a bevel pinion 56 'fixed to the lower end ofa. shaft 51. The shafts I and 51 are located directly above thetransmission I-I approximately at the center of the standard S. Theseshafts extend vertically upwardly through the top of standard S into thegear-bracket G. Referring to Fig. 3, the gear-bracket G comprises ahousing in the bottom of which bevel gears 58 and 59 are adapted to bejournaled. The gears 58 and 59 are fixed to the upper ends of shafts 5!and 51 respectively, and mesh with the bevel gears 88 and 6l keyed to apair of parallel hori- Zontally-disposed shafts 62 and 63. The parallelshafts 62 and 63 extend outwardly beyond the side of the standard S andare provided at'their outer ends with bevel gears 64 and 65 that meshwith bevel gears 68 and 61 keyed to the upper ends ofvertically-disposed parallel driving shafts 88 and 69. The sha-ft 68transmits rotary power from the transmission I-I to the feedworks F formoving the turret head T along its intersecting paths at a relativelyrapid, substantially constant speed. The shaft 69 is adapted to transmitrotary power to the feedworks F for moving the turret head T along itsintersecting paths at a plurality of relatively slow speeds. Both of theshafts 68 and 69 are splined throughout substantially their entirelengths to continuously supply rotary power to-the feedworks F as thelatter moves vertically with the movement of the cross-rail 32.

The feedworks F comprises a substantially rectangular box-like housing(Fig. 1) adapted to be hermetically sealed and to contain sufficientlubricant to keep the transmission gears submerged in oil, therebyinsuring adequate lubrication, noiseless operation and preventing dustand dirt from entering the transmission. The housing 10 is provided withsubstantially cylindrical bosses 1| and 12 (Figs. 2 and '1) throughwhich the vertically-disposed shafts 68 and 89 are adapted to pass.

Referring to Fig. 4, a bevel gear 13 is journaled in the cylindricalboss 12 and splined to the shaft 69. 'I'he bevel gear 13 meshes with abevel gear 14 keyed to a shafft 15. A portion 16 of the shaft 15 issplined to receive slidable gear units 11 and 18. The gear units 11 and18 are adapted to be selectively meshed with three gear units 19,80 and8| keyed to a shaft 82 parallel with shaft 15. The single gear of unit19 is adapted to mesh with one gear of unit 11; and the gear unit 80 isprovided with two gears, one of which is adapted to be meshed with agear of the sliding unit 11 and the other with a gear of the slidingunit 18. The gear unit 8l is provided with a gear adapted to be meshedwith one of the gears of @the slidable unit 18. From an inspection ofFig. 4, it is apparent that selective shiftingr of the slidable gearunits 11 and 18 will provide four separate and distinct rotative speedso-f shaft 82 from a single speed of shaft 15.

The rotative speeds provided by the transmission H for the feedworks F.require substantial reduction before they can be employed for feedingthe turret head T during a working operation. Accordingly, a speedreduction unit is contained within the transmission of the feedworks .F.Thel construction and arrangement i-s suchthat the speed of shaft 15 isreduced through a plurality of successive steps, at each of which adifferent driving rate for the feedworks F is produced. .The shafts 15and 82 of Fig. 4 are extended to support the speed-reduction unit of thetransmission. The gear unit 8| on the shaft 82 includes a relativelysmall gear 83 in constant mesh with arelatively large gear 84 freelyjournaled on the extension of shaft 15. Another relatively small gear 85integral with gear 84 is constantly in mesh with a relatively large gear86 freely journaled on the extension of shaft 82. A third relativelysmall gear 81, integral with gear 86, is also constantly in mesh with arelatively large gear 88.freely journaled on the shaft 15.- Thearrangement of gears 84, 85, 88, 81 and 88 may be continued indefinitelyto provide any desired number of successive steps of speed reduction.Inthe present instance, three steps are provided, each of which bears adefinite relation to the preceding and the following. A driven shaft89'is locatedwthin the feedworks F in parallel relation with the shafts15 and 82. Shaft 89 is actually in front of shaft 82 (Fig. 6), but forclarity, Fig. 4 discloses shaft 89 above shaft 82. A pair v`of gears 98and 9| are splined to the shaft 89. Movement of the gear 9| to the rightas viewed in Fig. 4 will provide four separate and distinct speeds ofshaft 89 upon selectively shifting the gear units 11 and 18. Movement ofgear `unit Sl to the left will produce an additional four speeds ofshaft 89 which speeds are reduced by the gear ratio of gears 83, 84, 85and 86, constituting the first step of the speed-reduction unit.Shifting gear 98 to the right will produce an additional four speedsupon selectively shifting gears 11 and 18. These speeds will be furtherreduced corresponding to the second speed-reduction step of the unit;and shifting gear 90 to the left will produce a final four speeds ofshaft 89 at the lowest rate the speed-reduction unit shown canaccomplish.l Accordingly, shaft 89 is adapted to be driven at sixteenseparate and distinct speeds by selectively shifting the gears 11, 18,9i and 90.

, The sixteen speeds of the shaft89 derived from shaft 69, as well asthe substantially constant speed of the shaft 68, are adapted to betransmitted .rto the driven shafts 35 and 48 for controlling themovement of the turret head T along itsintersecting paths. Furthermore,shafts 35 and 48 are adapted to be driven in both directions at aplurality of speeds of shaft 69 and the substantially constant speed ofshaft 68. 'In the present instance, this has been accomplished byproviding a transmission including a driving shaft for each of thedriven shafts 35 and 48 and a pair of auxiliary shafts, all of whichsupport the transmitting and the reversing mechanism.

Referring to Figs. 5 and 6, and particularly Fig. 5, the driven shaft 89is provided with` a gear 92 keyed thereto and adapted to constantly meshwith a gear 93 journaled on an auxiliary shaft 94. The gear 93 isadapted to drive a relatively long gear 95 likewise journaled on theshaft 94. An over-load clutch 96 is provided between the gears 93 and95, urged into engagement by a. spring 91 surrounding shaft 94. Therelatively long pinion 95 is adapted to partially overlie and mesh witha similar relatively long pinion 98 freely journaled on anotherauxiliary shaft 99. The auxiliary shafts 94 and 99 are located in asubstantially horizontal plane. A pair of driving shafts I08vand 10| arearranged in a substantially vertical plane that intersects thehorizontal plane midway between the shafts 94 and 99. The shafts and |0|are provided with a pair of driving gears |02 and |03 that areconstantly in mesh with the relatively long pinion 95 on the auxiliaryshaft 94; and a pair of driving gears |04 and |05 in constant mesh withthe relatively long pinion 98 on the auxiliary `shaft 99. Gears |02 and|04 are adapted to be rotated in opposite directions from that of gears03 and |05, and by selectively connecting-gears |02, |03, |04 and |05 tothe shafts |00 and |0|, it is apparent that said driving shafts may bedriven at sixteen different speeds in either direction upon selectivelyshifting the gears 11, 18, 90 and 9| of the variable speed unit. (Fig.4). Positiveaction axially-shiftable clutch members |06 and |01 aresplined to the driving shafts |00 and |0|, respectively. The slidable,positive-action clutchengaging means are adapted to cooperate withmating clutch elements |08, |09, ||0 and on the gears |02, |04, |03 and|051, respectively. The driving shafts |0| and |00 are adapted to drivethe screw shaft 35 and the splined shaft 40, respectively, forcontrolling the movementof the turret head T. Accordingly, intermeshingbevel gears ||2 and ||3 are fixed to the driving shaft |00 and splinedshaft 40, respectively, and intermeshing bevel gears ||4 and ||5 areadapted to be keyed to the driving shaft |0| and the screw shaft 35,respectively.

The driving shafts |00 and |0| are adapted to be rotated in oppositedirections at a constant, rapid traverse speed to move the turret head Ttoward and away from the work preparatory to a working operation.Accordingly, a bevel gear ||6 journaled in the substantially cylindricalboss 1| of the housing 10 is splined to shaft 68. Gear is adapted tomesh with a bevel gear ||1 integral with a stub shaft |8 that is coaxialwith the auxiliary shafi-l 94. A relatively long pinion I9 is adapted tobe keyed to the stub shaft ||8. A relatively long sleeve gear |20,provided with gear portions |2| and |22, is adapted to be journaled onthe auxiliary shaft 99-the gear portion |2| meshing with the relativelylong pinion ||9. Accordingly, pinion ||9 and gear |20 are rotated inopposite directions. Gears |23 and |24, journaled on the driving shaffts|00 and |0|, respectively, are maintained in constant mesh with thepinion H9; and similar gears |25 and |26, journaled on the drivingshafts |00 and |0|, respectively, are adapted to be maintained inconstant mesh with the gear portion |22 of the sleeve gear |20.

Axiallyshiftable positive-action clutch members |21 and |28 (similar toclutch members |06 and |01) are splined to the driving shafts |00 and|3|, respectively, between the gears |25, |23 and |20, |24. The clutchmembers-|21 and |28 are adapted to engage corresponding or mating clutchmembers on adjacent sides of gears |25, |23 and |26, |24 respectively.Accordingly, by selectively shifting the clutch members |21 and |28, itis possible to drive the driving shafts |00 and i0! in either directionat a constant, relatively-rapid traverse speed.

u The mechanism for selectively shifting the clutch elements |06 and |21is identical with that for shifting the elements |01 and |28, and forthat reason, only the shifting mechanism for the clutch elements |06 and|21 will be described. Referring to Figs. 6 and 7, shiftable elements|08 and |21 are provided with yoke elements'or members -|2|) and |30.respectively.A The yoke |29 is oscillatably mounted on a shaft |3|within the housing 10. In a similar manner, the yoke |30 is oscillatablymounted on a shaft |32. The yoke member |29 is provided with an arm |33bored to receive a shaft |34 that is journaled in a bearing |35 mountedin the housing 10. The bore that receives shaft |34 is slightly largerthan Vthe diameter of the shaft providing a loose connection, and a pin|36 is provided between the arm |33 and the shaft |34. The loosenessbetween the bore of arm |33 and the shaft |34 is necessary toaccommodate the angularity produced by the oscillatable movement of theyoke member |29. The shaft |34 extends from the left side of the arm |33(Fig. '7) into a cylinder |31, within which a piston |38, fixed to theshaft |34, is adapted to be reciprocated. The portion of shaft 34 thatextends within the cylinder |31 is reduced in diameter to provide ashoulder |39, and a plate |40 of slightly larger diameter than thereduced diameter of the shaft |34 is fixed to the end of shaft |34within cylinder |31 by a locking bolt An auxiliary cylinder |42 ismounted within the cylinder 31 and forms a chamber |43 Within whichpiston members |44 and |45 are adapted to reciprocate. The members |44and |45 are loosely mounted on the reduced diameter of the shaft |34.The piston member |44 is adapted to abut against the plate |40 as wellas against a ring member |46 that holds the auxiliary cylinder |42 inplace. The piston member |45 is adapted to abut against the shoulder |39formed between the reduced diameter of shaft |34 and its largestdiameter. The cylinder |31 is provided with ports |41 and |48 onopposite sides of the piston |38. The ports |41 and |48 are connected toconduits |49 and |50 that communicate with a source of fluid underpressure. The auxiliary cylinder |42 is provided with a port |5| betweenthe piston members |44 and |45. Port |5| communicates with a line |52which latter communicates with a source of fluid under pressure.

Fluid, preferably liquid, under pressure is adapted to be supplied tothe conduit |52 at all times thereby tending to separate the pistonmembers |44 and |45 so that the yoke |29 is always urged towards aneutral position. Fluid under pressure is adapted selectively to besupplied to conduits |49 and |50 by mechanism to be described later, forshifting the piston |38 to the right or left thereby shifting the yoke|29 to effect engagement between the clutch |06 and the gears |04 and|02. It is to be noted that the area of the piston |38 on which thefluid under pressure is adapted to act is substantially greater than thearea of the piston members |44 and |45 against which said fluid pressureis adapted to act. Accordinglyyalthough a constant supply of fluid underpressure is delivered through the conduit |52, tending to neutralize theclutch |06, any admission of fluid under pressure to either side of thepiston |38 will cause it to move in the selected direction. and uponrelease of -such pressure the clutch |06 is immediately returnedtoneutral position due to the action of the piston members |44 and |45.

In a like manner, the yoke member |30 is provided with an arm |53 fixedto a shaft |54 in the same manner that shaft |34 is fixed to arm |33.Shaft |54 is likewise Yprovided with a piston |55 that reciprocateswithin a portion of a cylinder |56, and neutralizing pistons |51 and |58are provided for the yoke |30 which function in an identical manner withpiston members |44 and |45. Fluid under pressure is adapted selectivelyto be admitted to opposite sides of the piston I 55 while a constantsource of iiuid under pressure is delivered between the pistons |51 and|58 at all times.

Referring to Fig. 8, the shiftable elements 11, 18, 9| and 90 which areadapted, upon shifting, to provide Sixteen different speeds of rotationof the gear 92 (Fig. 5), are adapted to be shifted by the movement ofnger elements |65, |66, |61 and |68. Four parallel rods |69, |10, |1|and |12 are mounted for reciprocation in bearings within the housing 10.The finger element |65 is pinned to the rod |10; the finger element |66is pinned to the rod |69; the element |61 is pinned to the rod |1|; andthe element |68 is pinned to the rod |12. Accordingly, selective axialmovement of the rods |69 to |12, inclusive, will effect selectiveshifting of the slidable gear units 11, 18, 9| and 90.

Since each of the rods |69 to |12, inclusive, is adapted to be shiftedaxially in the same manner by identical means, only the means forshifting rod |12 will be specifically described. The rod |12 is adaptedto extend into a cylinder |13, and a piston |14 is fixed to rod |12 forreciprocation Within said cylinder. Ports |15, |16 are provided in thecylinder |13 for selectively admitting fluid under pressure to oppositesides of the piston |14. The end of the rod |12 nearest the piston |14is provided with a groove |11 that is adapted to cooperate with a groove|18 in the end of rod |1| adjacent to rod |12. A drilled passage |19 isprovided in the housing for the cylinders |13, and balls |19 are locatedwithin the passage |19. The construction is such that neither of therods |1| or |12 can be shifted from its neutral position if the otherrod is out of its neutral position.

The portion of the rod |12 at the end thereof opposite that to which thepiston |14 is connected, is reduced in diameter forming a shoulder |80against which a loosely mounted piston member |8| is adapted to abut. Anadditional piston member |82 on the reduced portion of the shaft |12 isadapted to engage a plate |83 fixed to the end of shaft |12 by a lockingbolt |84. The area of piston members |8| and |82 is substantially lessthan that of piston |14. A line |85 is connected to a drilled passage inthe housing surrounding the cylinder within which the piston members |8|and |82 are adapted to reciprocate. so that fiuid under pressure may beconstantly delivered into the cylinder within which said piston membersreciprocate. Each of the rods |69 to |12, inclusive, is provided withthe same type of neutralizing mechanism which is substantially the sameas that disclosed in connection with the rods |34 and |54 of Fig. 7. Thepassage to which line |85 is connected extends completely through thatportion of the housing member in which the cylinders are provided forthe respective neutralizing mechanism so that at all times, fluid underpressure is adapted to act upon the individual piston elements thereof.Accordingly, upon the selective admission of iiuid under pressure to theopposite sides of the pistons |14 on the respective rods |69 to |12,inclusive, said rods will be axially moved in the direction dictated bythe sides of the pistons against which the fiuid is directed, and,immediately upon the release of such pressure, each of the neutralizingmechanisms for the rods |69 to |12, inclusive, will automatically shiftinto neutral the shiftable gear units11, 18, 9| and 90 with which saidrods are associated.

For a better understanding of the fluid system that interconnects theuid motors attached to clutches |06, |01, |21 and |28, as well as thoseattached to the gear-shifting rods |69, |10, |1| and |12, attention isdirected to Figures 9 and 10 in which the apparatus is schematicallydisclosed. Referring to said figures, a valve body |86, provided with aplurality of valve plungers |88 to 203, inclusive, is adapted to besupplied with liquid under pressure from a source S (Fig. 10) throughthe line |85. The valve body |86 is provided with a passage |81extending longitudinally therethrough for supplying all of the bores forvalves |88 to 203 with liquid under pressure. The valveplungers |88 to|99, inclusive, are identical, while valve plungers 200 to 203,inclusive, are identical but different from the former group. One valveof each of these groups will be specifically described later. For thepresent, it is only necessary to note that each valve plunger isprovided with a supply line and an exhaust.

The bore for valve plunger |88 is connected to the one end of line I 15,the opposite end of which is connected to the right-hand side of thecylinf der in which piston |14 is adapted to reciprocate (Fig. 19). Thebore for valve plunger |89 is connected to the one end of line |16,while the other end of said line is connected to the left-hand side ofthe cylinder in which piston |14 is adapted to be reciprocated. The line|85 which continuously supplies iiuid under pressure to the valve body|86 also continuously supplies fluid under pressure to the cylinder inwhich piston elements |8| and |82 are adapted to be reciprocated. Aspreviously pointed out, the effective areas of pistons |8| and |82 aresubstantially less than that of piston |14. Therefore, with valveplungers |88, 89 in their lower position as shown in Fig. 9, lines |15an-d |16 are open to exhaust ports |15', |16', and the pressure fluidthat continuously acts on piston members |8|, |82 maintains piston |14midway of its stroke and gear element 90 in neutral. Movement of eithervalve |88 or |89 to its upper position cuts off the exhaust and admitsliquid under pressure to either side of piston |14, thereupon gear 90moves to the right or left depending upon which valve, I 88 or |89, israised. v

In a like manner, valve plungers |90, |9| con trol the admission ofliquid under pressure to, and exhaust from both sides of piston 204through lines 205, 206, and consequently the shifting of gear 9|; valveplungers |92, |93 control the fiow of liquid through lines 208, 209, andconsequently the movement of gear 18; valve plungers |94, |95 controlthe flow of liquid through lines 2| I, 2|2, and consequently themovement of gear 11; valve plungers |96, |91 control the flow of liquidthrough lines |49, |50, and consequently the movement of clutch |06;valve plungers |98, |99 control the ow of liquid through lines 2|4, 2|5,and consequently the movement of clutch |01; valve plungers 200, 20|control the flow 0f liquid through lines 2|6, 2|1, and consequently themovement of clutch |21; and finally, valve plungers 202, 203 control theflow of liquid through lines 2|9, 220, and consequently the movement ofclutch |28.

Not only is the line |85 adapted continuously to supply liquid underpressure to valve body |86 and the cylinder within which piston elements|8|, |82 reciprocate, but itis also adapted con-

